Because it's actually used in the manner and for the sort of purposes cards are presently used - not at all in the way cash is used.
It is, in fact, strictly worse than cash - because it's more irreversible (I'm unlikely to be able to pluck cash out of your pocket from halfway around the world), yet more traceable. (The blockchain as "prosecution futures".)
It is, in fact, strictly worse than cash - because it's more irreversible (I'm unlikely to be able to pluck cash out of your pocket from halfway around the world), yet more traceable. (The blockchain as "prosecution futures".)